This invention relates, generally, to devices for damping or cushioning the movement between two objects moving relative to one another, and relates more particularly to a new and improved dashpot type of damper.
The type of damper with which this invention is concerned commonly includes a housing assembly defining an elongated cavity for containing hydraulic fluid and a piston assembly having a head received by the elongated cavity for sliding movement in either of two directions therealong. The housing assembly is connectable to one of two objects movable toward or away from one another, and the piston assembly is connectable to the other of the two objects. The piston head is arranged in the elongated cavity so as to separate the cavity into two variable-volume chambers, and the housing assembly includes a network of hydraulic fluid flow passages in flow communication with the first and second chambers. As the two objects move toward one another, the piston moves in one direction relative to and along the cavity to force hydraulic fluid through the flow passages from one of the variable-volume chambers to the other. Similarly, as the two objects move away from one another, the piston moves in the other direction relative to and along the cavity to force hydraulic fluid through the flow passages from said other of the varible-volume chambers to said one chamber. For purposes of adjusting the damping or cushioning effect of a damper of the aforesaid described type, the damper includes adjustment mechanisms for varying the size or configuration of its flow passages to thereby vary the flow characteristics of hydraulic fluid moving between the two variable-volume chambers.
In the past, damper selection required extensive engineering time to determine the proper parmeters under which a damper could best be utilized, with extensive testing, modification and re-testing. Accordingly, it would be highly desirable to provide a damper which substantially reduces complex motion analysis by allowing the user to determine an optimum setting, and then lock the damper in that position with a plug-in type self-contained unit, the unit allowing damping to be programmed or pre-determined for tension, compression or both, and the unit enabling the damper to be adjustable in compression and free-flow in tension or adjustable in tension and free flow in compression or both.